Induction machine Research Papers - Academia.edu (original) (raw)

We present a case study of Machine Learning and Data Mining in intensive care medicine. In the study, we compared different methods of measuring pressure-volume curves in artificially ventilated patients suffering from the Adult... more

- by
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- Engineering, Artificial Intelligence, Machine Learning, Data Mining

This paper investigates the utilization of three different configurations of induction motor drives to implement low-cost systems for low-power applications. The static power converter side is implemented by a single-phase rectifier cascaded with a four-switch inverter. Three different types of induction machines are supplied with the static power converter. In the first configuration, a standard three-phase induction machine is employed. The second configuration also employs a standard three-phase induction machine, but only two of three windings are used. In the third configuration, a standard two-phase induction machine is employed. Simulation and experimental results are provided to illustrate the operation of the systems.

- by Edison Silva
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- Engineering, Industry, Low Power, Induction machine

This paper presents a new method to measure motor speed by means of frequency estimation of rotor slot spectral components in the supply current of squirrel single-cage induction motors. The novelty of the method consists in the harmonic analysis of the supply current by means of the chirp-Z transform (CZT). The advantages are improved accuracy due to better spectral resolution and resolvability. Moreover, a shorter observation window is required, thus reducing errors related to nonstationary current signals. The experimental results are presented to validate the proposed method and to make a comparison with a similar method based on the fast Fourier transform (FFT).

- by Antonio Cataliotti
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- Harmonic Analysis, Frequency Estimation, Induction machine, Induction Motor
- by Soumitro Banerjee
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- Nonlinear dynamics, Bifurcation theory, Bifurcation, Autonomic System

Despite the ability of matrix converters (MCs) to generate a higher number of voltage vectors compared with standard voltage-source inverters, most of the applications reported in the literature utilize only those having larger amplitudes. This paper investigates the use of MC input voltages with different amplitudes in order to reduce the inherent torque ripple that appears when direct torque control (DTC) is used to drive ac machines, particularly permanent-magnet synchronous motors, as its stator inductance is typically half of that of an induction machine of similar ratings. Utilizing a wider range of input voltage vectors for the MC, but not using the rotating vectors, a new lookup table that distinguishes between small and large torque errors is developed, leading to an enhanced MC-fed DTC. The enhancement enables a reduction in the electromagnetic torque ripple and outputcurrent total harmonic distortion. Furthermore, the proposed control strategy improves the MC voltage transfer ratio up to 86.6% compared with 50% achieved by the conventional DTC using MCs at the expense, however, of slightly decreasing the input power factor control capability. The proposed enhanced MC DTC was tested experimentally, and results comparing its performance with MC DTC using an adapted lookup table are shown.

- by Carlos Ortega
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- Engineering, Control Strategy, Induction machine, Matrix Converter

This paper describes the dynamic behaviour of a doubly-fed induction machine, operating with wind turbine. The rotor circuit of the machine consists only of a generator-side converter working under abnormal condition at stator side (fault condition and voltage drop take place in transmission lines of the grid system). The induction machine model is based on the stationary reference frame and the control-unit model is based on the line-voltage oriented reference frame. The generator-side controller provides good decoupling between active and reactive power. A powerful MATLAB/SIMULINK was used for the simulation of the wind energy conversion system of a 4 kW wind generator. The simulation results of the generator side converter show that the speed, torque and the ϕ sin (power factor) can be regulated independently to match the reference signals. The effects of assumed abnormal condition in the grid system are discussed with regard to stator current and rotor current of the induction m...

- by Somchai Chatratana
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- Wind turbine, Reactive Power, Oscillations, Wind energy conversion system

In this paper, a transient model of the faulty machine is developed. The model is referred to a three phase stator winding, while the rotor has been represented by all the meshes allowing for the representation of various faults. The model is based on coupled magnetic circuit theory by considering that the current in each bar is an independent variable. The model incorporates non-sinusoidal air-gap magneto motive force (MMF) produced by both stator and rotor, therefore it will include all the space harmonics in the machine. Simulations and experimental results were then used to study rotor faults cause-effect relationships in the stator current and the frequency signature.

- by Tarek Aroui and +1
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- Spectrum, Leonardo, Induction machine, Magnetic Resonance Coupling

Field-oriented control methodology requires knowledge of the machine parameters and, in particular, the rotor time constant. The interest here is in tracking the value of T R as it changes due to ohmic heating so that an accurate value is available to estimate the rotor flux linkages for a field-oriented controller. The approach presented here uses a nonlinear least-squares approach using measurements of the stator currents and voltages along with the rotor speed. The nature of this technique lends itself directly to an online implementation and therefore can be used to track the rotor time constant. Experimental results are presented to demonstrate the validity of the approach.

- by Marc Bodson
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- Proceedings, Constant Time Delay, Induction machine

A significant number of studies have been reported in the literature on the detection of eccentricity faults in induction machines; however these have generally used one type of sensor such as current or vibration, and not studied in detail the effect of loading. This paper examines the use of fault frequency components in the current, flux and vibration sensor signals with the aim of both detecting and estimating the severity of static eccentricity faults in the presence of load variations. The research is based on an extensive series of sensor measurements taken using a specially modified 2.2kW induction machine under varying conditions of static eccentricity and loading.

- by Colin Hansen
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- Induction machine, Induction Motor

The phenomenon of saturation of electric machines constitutes an important subject of investigation in electrical engineering. This paper presents a new modeling technique for saturation in the case of induction machines. Necessary calculations to introduce this technique in the linear flux model are presented. Computed results and experimental tests on the transients of the self-excited induction generator are clearly compared. These experimental and computed results agree closely, validating the proposed technique as well as the developed model.

- by O. Touhami
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- Electrical Engineering, Electrical Machine, Induction machine, Experimental Tests

In order to mitigate the adverse effects of starting torque transients and high inrush currents in induction motors, a popular method is to use electronically controlled soft-starting voltages utilizing series-connected silicon-controlled rectifiers (SCRs). Investigation of semioptimum soft-starting voltage profiles was implemented using a flux linkage ABC frame of reference model of a soft-started three-phase induction motor. A state-space model of the soft-starter thyristor switching sequence for the motor and load was developed and implemented in a time-domain simulation to examine winding heating and shaft stress issues for different starting profiles. Simulation results of line starts and soft starts were compared with measured data through which validation of the model was established. In this paper, different induction machine soft-start profiles are shown, and comparisons of starting times, torque profiles, and heating losses are made. Discussion of these results and conclusions as to the near-optimum types of profiles are delineated based on peak torque, starting times, and winding heating criteria.

- by Behrooz Mirafzal
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- Engineering, Electrical Machine, Induction machine, Induction Motor

In today's data-centric world many applications rely on data that comes from multitude of different sources. To integrate that data two major operations are performed: finding semantic mapping between data sources, and transforming structure of the data sources. One of the well-established standards for storing and sharing structured and semantically described data is XML. This paper describes system called XMapper, which is used to generate semantic mapping between two XML sources that describe instances from the same domain. The described system is novel in two ways. It uses only stand-alone XML documents (without DTD or XML schema documents) to generate the mappings. It also utilizes machine learning to improve accuracy of such mappings for difficult domains. Several experiments that use artificial and real-life domains described by XML documents are used to test the proposed system. The results show that mappings generated by the XMapper are highly accurate for both types of XML sources. The generated mappings can be used by a data integration system to automatically merge content of XML data sources to provide unified information for a data processing application.

- by Waldemar Swiercz
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- Machine Learning, XML Schema, Semantic Mapping, Data Integrity

A stability study of an induction machine is performed by applying the root-locus criterion to the equations which describe the behavior of the machine during small displacements about a steady-state operating point. This investigation reveals that a symmetrical induction machine may become unstable at low speeds (low frequencies) even though balanced, constant amplitude, sinusoidal voltages are applied to the stator terminals. Regions of machine instability are established from the results of a digital computer study. The results of an analog computer study are included to illustrate the modes of operation which occur within these regions. Regions of instability for changes of system parameters are presented and discussed. Also, it is shown that the rootlocus criterion can be utilized to identify regions of lightly damped operation.

- by Thomas Lipo
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- Low Frequency, Stability Analysis, Steady state, Induction machine

This paper develops a simple sensorless control algorithm for an induction motor. An observerless controller is proposed, which guarantees local asymptotic speed tracking-flux regulation under condition of constant load torque. The controller development is based on the decomposition of the induction machine model in two coupled subsystems: electromechanical and electromagnetic, achieved by means of indirect field-oriented transformation. The experimental results demonstrate the steady-state and dynamic performance suitable for general industrial applications.

This paper presents a sensorless technique for highperformance induction machine drives based on neural networks. It proposes a reduced order speed observer where the speed is estimated with a new generalized least-squares technique based on the minor component analysis (MCA) EXIN + neuron. With this regard, the main original aspects of this work are the development of two original choices of the gain matrix of the observer, one of which guarantees the poles of the observer to be fixed on one point of the negative real semi-axis in spite of rotor speed, and the adoption of a completely new speed estimation law based on the MCA EXIN + neuron. The methodology has been verified experimentally on a rotor flux oriented vector controlled drive and has proven to work at very low operating speed at no-load and rated load (down to 3 rad/s corresponding to 28.6 rpm), to have good estimation accuracy both in speed transient and in steady-state and to work correctly at zero-speed, at no-load, and at medium loads. A comparison with the classic full-order adaptive observer under the same working conditions has proven that the proposed observer exhibits a better performance in terms of lowest working speed and zero-speed operation.

- by Gerard-Andre Capolino
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- Engineering, Neural Network, Working Conditions, Steady state

In this paper, a method is presented for removing the risk associated with the testing and development of novel drive system topologies, prototype electrical machines, advanced control system strategies, or a combination of the aforementioned without using any real motors/generators. The test platforms for low-power machines are relatively inexpensive and accessible; however, as power levels increase into the upper kilowatt and megawatt range, validation of prototype machines and drives becomes costly. The proposed induction machine emulator (IME) platform utilizes the power hardware-in-the-loop concept in conjunction with a highfidelity machine model and load dynamics. The electrical machine and its load dynamics are simulated with a real-time digital simulator, which generates appropriate control commands to a power electronics-based voltage amplifier that interfaces to a variable speed drive (VSD). Specifically, the current draw is recreated by altering the phase and magnitude of a voltage amplifier connected to a VSD under test via a unique transformer-based LCL-type coupling network. Based on the proposed concept, the use of a multiwinding, tap-changing transformer establishes a truly versatile and universal test platform for a wide range of power levels. In addition, this paper presents a control strategy in the synchronously rotating reference frame in dq coordinates for the power electronic converters in IME operation. Experimental results at the 25-kVA power level validate the feasibility and highly dynamic performance of the proposed test platform. Index Terms-Induction machine (IM), power hardware-in-theloop (PHIL), ripple filter, variable speed drives (VSDs), voltage source inverter (VSI).

- by Chris Edrington
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- Power Electronics, Computational Modeling, Embedded Systems, Control system

This paper derives the analytical characterization of Maxwell radial vibrations due to saturation effects in induction machines, and especially in traction motors. The number of nodes and the velocity of these particular force waves are experimentally validated by visualizing some operational deflection shapes of the stator. It is shown that according to the stator and rotor slot numbers, and stator natural frequencies, these forces can be responsible for high magnetic noise levels during electrical starting and braking. A simple rule to avoid saturation magnetic noise is then proposed, and applied to an industrial motor. A fully analytical model of the motor vibro-acoustic behavior, including saturation effects, is finally presented. Simulation results show that the new proposed motor improves magnetic noise level up to 20 dB, whereas experiments give a 15 dB improvement.

- by vincent lanfranchi
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- Engineering, Vibrations, Vibration, Physical sciences

Induction motor (IM) speed sensorless control, allowing operation at low and zero speed, optimizing torque response and efficiency, will be presented in this paper. The magnitude and the orientation angle of the rotor flux of the IM are determined by the output of the closed-loop rotor-flux observer based on the calculation of the extended electromotive force of the machine. The proposed rotor-flux-oriented control scheme is robust to parameter variations and external disturbances. Both observer and controller utilize the continuous sliding mode and Lyapunov theory. A smooth transition into the field-weakening region and the full utilization of the inverter current and voltage capability are thus possible. The produced torque is a continuous output variable of control. The performance of the proposed method is investigated and verified experimentally on a digital signal processor.

- by Karel Jezernik
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- Engineering, Digital Signal Processor, Sensorless Control, Induction machine

This work deals with the design of an Adaptive Reference model Controller for (MRAC) for parameters adaptation apply to an indirect field oriented controller for induction motor control. The parameters behavior was analyzed using three different reference models. The considered reference models were: direct (d) axis voltage, the quadrature (q) axis voltage and the reactive power. For each reference model the adaptation error was analyzed. Using these equations the parameters convergence was analyzed and discussed under several motor conditions. The results were presented and the simulation for all the reference models considered, illustrating the parameters behavior under several motor operating conditions. The analysis and simulation results show the superiority of the dynamic reference models using quadrature (q) axis voltage and reactive power model.

- by Aldo Garcia
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- Reactive Power, Reference model, Constant Time Delay, Operant Conditioning

This paper describes a model for a six-phase induction motor driven by an inverter operating in a six-pulse (square wave) mode. The model is implemented, and performance, in terms of torque, current, and efficiency, is compared to the performance of a three-phase motor (supplied with either a sine and six-pulse voltage). The models are verified experimentally to a degree of accuracy, and it is illustrated that the improvement in inverter efficiency when in six-pulse operating mode may improve the performance of the overall system, although the improvement is marginal in the example used. The potential of this drive configuration is demonstrated.

- by David Dorrell
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- Engineering, Performance Assessment, Induction machine, Induction Motor

Remote sensing is a geographic analysis tool capable of producing large quantities of data in the spectral, temporal and spatial domains. Techniques for automating the image analysis process would be advanced by the inclusion of artificial intelligence techniques in the design of image processing systems. The remote sensing applications which show promise for successful implementation of artificial intelligence techniques are intelligent onboard processing. advanced database interrogation, and the automated analysis of multispectral imagery.

- by Rishav Sharma
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- Human Geography, Computer Science, Artificial Intelligence, Image Processing

Motor-current-signature analysis has been successfully used in induction machines for fault diagnosis. The method, however, does not always achieve good results when the speed or the load torque is not constant, because this causes variations on the motor-slip and fast Fourier transform problems appear due to a nonstationary signal. This paper proposes a new method for motor fault detection, which analyzes the spectrogram based on a short-time Fourier transform and a further combination of wavelet and power-spectral-density (PSD) techniques, which consume a smaller amount of processing power. The proposed algorithms have been applied to detect broken rotor bars as well as shorted turns. Besides, a merit factor based on PSD is introduced as a novel approach for condition monitoring, and a further implementation of the algorithm is proposed. Theoretical development and experimental results are provided to support the research.

- by Luis Romeral
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- Engineering, Fault Detection, Condition Monitoring, Fault diagnosis

A general model suitable for the vector control of the unsymmetrical two-phase induction machines is presented in the paper. Both the rotor flux oriented and the stator flux oriented control strategies are analysed and their suitability for low and high-speed operation is discussed. In the mathematical model the machine main and auxiliary winding are represented in the stationary reference frame and the effect of core losses and the main flux path saturation are included. A special technique is used to model different levels of saturation on the two axes of magnetisation. The model can be employed for the accurate simulation of both the steady-state and the transient operation of the unsymmetrical two-phase induction machines.

- by David Dorrell and +2
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- Electric machines, Reference Frame, Steady state, Vector control

This paper presents a new signature for detection of rotor faults in induction motors, such as eccentricity and broken rotor bars, that uses the external magnetic field analysis. The proposed method is based on the variations of axial flux density in the presence of these faults. The low frequency part of the magnetic field spectrum is particularly analyzed. The analysis

- by Rémus Pusca
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- Engineering, Low Frequency, Magnetic field, Spectral analysis

This paper presents the modeling, simulation, and analysis of the dynamic behavior of a fictitious 2 × 320 MW variable-speed pump-turbine power plant, including a hydraulic system, electrical equipment, rotating inertias, and control systems. The modeling of the hydraulic and electrical components of the power plant is presented. The dynamic performances of a control strategy in generating mode and one in pumping mode are investigated by the simulation of the complete models in the case of change of active power set points. Then, a pseudocontinuous model of the converters feeding the rotor circuits is described. Due to this simplification, the simulation time can be reduced drastically (approximately factor 60). A first validation of the simplified model of the converters is obtained by comparison of the simulated results coming from the simplified and complete models for different modes of operation of the power plant. Experimental results performed on a 2.2-kW low-power test bench are also compared with the simulated results coming from both complete and simplified models related to this case and confirm the validity of the proposed simplified approach for the converters.

- by Philippe Allenbach
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- Engineering, Power Plant, Control system, Dynamic Simulation

- by Lukasz Kurgan and +1
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- Machine Learning, XML Schema, Semantic Mapping, Data Integrity

The performance of doubly fed induction generator (DFIG) variable speed wind turbine under network fault is studied using simulator developed in MATLAB/SIMULINK. Simulation results show the transient behavior of the doubly fed induction generator when a sudden short circuit at the generator bus is introduced. After the clearance of the short-circuit fault the control schemes manage to restore the wind

- by Naggar Saad
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- Electric Power Systems, Wind turbine, Dynamic Response, Induction machine

The surge test is a well-known offline method to determine the integrity of the turn-to-turn insulation of coils as they are found in transformers or induction machines. There are different methods used to evaluate the waveform obtained during the surge test. These methods include the examination of the zero crossings of the waveform, i.e., its ringing frequency, the differential error area ratio (EAR) also known as the pulse-topulse EAR (P-P EAR) or a corona evaluation. A semi-analytical derivation of the P-P EAR under healthy and faulty conditions as well as a definition of the frequency and EAR sensitivity is given in this paper to gain more insight into the evaluation of the ringing frequency and the P-P EAR. The derivations shown in this paper are supported by simulations and experimental results.

- by Jose Restrepo
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- Sensitivity Analysis, Mathematical Model, Sensitivity, Corona

This paper deals with the synthesis of a stabilizing Backstepping nonlinear control provided with an adaptive Backstepping observer to estimate the rotor flux of an Induction Machine (IM). This approach is based on the vector control strategy by replacing the existing conventional controller with a Backstepping control in order to more quickly bring back the qaxis flux towards zero and to reduce the effect of the motor parameters variations. To observe the rotor flux, we have introduced an observer based on the Backstepping theory provided with an adaptive mechanism of rotor resistance. The design principle of the controlled system is established using the Lyapunov stability theory.

- by Faouzi M'SAHLI
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- Adaptive Control, Automation & COntrol, Nonlinear Control, Resistance

This work has developed a steady-state and dynamic mathematical model of three phase slipring induction motors with external impedance. Differential equations are solved using computer simulation and data for an induction machine are obtained from laboratory tests. It is shown that harmonics due to impedance asymmetry produce changes on the electromagnetic torque and induce harmonic frequency currents in the stator windings. Voltage equations are given by: dEd cy1 = [RIP1 + 7 where: m] = phase resistance matrix. B. Eiecpomagnetic torque equation 0-7803-3946-0/97/S1O.D0 0 1997 IEEE. MB1-1.1

- by Luciano Neto
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- Differential Equations, Computer Simulation, Steady state, Impedance

The minimum and maximum excitation capacitance required for a self excited single phase induction generator using a three phase machine has been determined by an eigenvalue and eigenvalue sensitivity approach. It is observed that the required minimum capacitance reduces with the increase in load. Traditionally, the minimum and maximum capacitances required for a self excited induction generator (SEIG) were solved by a high order non-linear polynomial equation based on a per phase equivalent circuit model. The advantage of this proposed method is its simplicity since the complicated solution procedure of the high order polynomial is avoided. The generator consists of a three phase star connected induction machine with three capacitors connected in series and parallel with a single phase load. The developed dynamic model of the SEIG is based on the stationary reference frame d-q axes theory, and the equations of the excitation capacitors are described by a three phase abc model assuming a constant speed prime mover. The capacitance values obtained by the proposed method have been compared with those obtained by the conventional method and verified experimentally to confirm the validity and the accuracy of the proposed method.

- by Mahendra Pal Sharma
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- Equivalent Circuit, Reference Frame, Eigenvalues, Induction machine
- by Surya Santoso and +1
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- Distributed System, Power system distribution, Transient analysis, Steady state

The paper presents a new double layer three phase 4 to 6 pole-changing winding, with 48 slots and 6 terminals. In order to obtain a higher fundamental winding factor when winding is 6-pole connected, a degree of asymmetry is accepted for the winding when 4-pole connected. The new winding is compared with a well known two-layer winding presented in literature.

- by Ovidiu Craiu
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- Finite element method, Double Layer, Electrical Machine, Induction machine

Numerical impulse response test to estimate circuit-model parameters for induction machines.

This paper deals with a new experimental approach to the parameter estimation of induction motors with least-squares techniques. In particular, it exploits the robustness of total leastsquares (TLS) techniques in noisy environments by using a new neuron, the TLS EXIN, which is easily implemented online. After showing that ordinary least-squares (OLS) algorithms, classically employed in the literature, are quite unreliable in the presence of noisy measurements, which is not the case for TLS, the TLS EXIN neuron is applied numerically and experimentally for retrieving the parameters of an induction motor by means of a test bench. Additionally, for the case of very noisy data, a refinement of the TLS estimation has been obtained by the application of a constrained optimization algorithm which explicitly takes into account the relationships among the K-parameters. The strength of this approach and the enhancement obtained is fully demonstrated first numerically and then verified experimentally.

- by Gerard-Andre Capolino
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- Engineering, Neural Network, Parameter estimation, Induction machine

Brushless doubly fed iuduction machine has recently attracted attention in variable speed generators and motor drives. In order to have a high performance control, a precise dynamic model is required. This paper aims at introducing a model of brushless doubly fed induction machine taking core loss into account. The details of model derivation are outlined and the torque relation is expressed in the general reference frame. The model is then used for simulation of the dynamic performance of the machine. The error introduced by neglecting core loss effect is also shown.

- by Antoni Arias
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- Engineering, Control Strategy, Induction machine, Matrix Converter

This paper investigates diagnostic techniques for electrical machines with special reference to induction machines and to papers published in the last ten years. A comprehensive list of references is reported and examined, and research activities classified into four main topics: 1) electrical faults; 2) mechanical faults; 3) signal processing for analysis and monitoring; and 4) artificial intelligence and decision-making techniques.

- by Gerard-Andre Capolino
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- Engineering, Decision Making, Signal Processing, Pattern Recognition

Due to the potential benefits resulting from the use of a phase order higher than three in transmission, some interest has also grown in the area of multi-phase machine. For machine drive applications, multi-phase system could potentially meet the demand for high power electric drive systems, which are both rugged and energy-efficient. High phase number drives possess several advantages over conventional three-phase drives such as: reducing the amplitude and increasing the frequency of torque pulsation, reducing the rotor harmonic currents, reducing the current per phase without increasing the voltage per phase, lowering the dc link current harmonics, higher reliability and increased power in the same frame. The high phase order drive is likely to remain limited to specialized applications where high reliability is demanded such as electric/hybrid vehicles, aerospace applications, ship propulsion, and high power application where a combination of several solid state devices form one leg of the drive. The research has been underway for the last two decades to investigate the various issues related to the use of multi-phase machine as a potential alternative to the conventional three-phase machine. This paper, therefore, reviews the progress made in multi-phase induction machine drive research and development since its inception. Attempts are made to highlight the current and future issues involved for the development of multi-phase induction machine drive technology for future application. : S 0 3 7 8 -7 7 9 6 ( 0 2 ) 0 0 0 0 7 -X

- by Moshe Rudowski
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- Modeling, Stability, Electric Power Systems, Hybrid Vehicle

In Brazilian rural areas single-phase power supply is very common. Single-phase induction motors with reasonable power are used to run farming activities which often, depending of their size, is not an inexpensive option. The aim of this work is to provide to farmers a simple, inexpensive and reliable option by running a modified threephase induction motor with as little structural modification as possible in order to run it with the available single-phase power supply. The asymmetrical three-phase induction machine fed by a single phase source, already discussed in previous work [1], has nothing more than an ordinary squirrel cage rotor and a stator where three-phase windings are located. These windings have the ordinary spatial design with a displacement of 120 0 between them, but with a different number of turns in each phase. With a proper relation of number of turns in each phase and with the help of a capacitor (Cap) connected between phases B and C, as in , can be possible to make the asymmetrical induction motor to produce nominal power at nominal speed.

- by Luciano Neto
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- Power Supply, Induction machine, Induction Motor, Rural Area

- A usual argument against GPC is its demand for processing power. In industry, however, this is not a serious argument if better control performance can be reached. As the development of new processors with increased performance takes... more

- by Ralph Kennel
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- Control Systems, Sampling methods, Error Correction, Predictive models

Multivariable supervision systems for online monitoring of induction motors allow large versatility and diagnosis robustness. As regards rotor faults, the diagnostic procedure based on sideband current components may fail due to the presence of interbar currents that reduce the degree of rotor asymmetry and, thus, the amplitude of these spectral components. On the other hand, the interbar currents produce core

- by Carlo Concari
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- Engineering, Condition Monitoring, Differential Diagnosis, Fault analysis

Generation of DSP-based patterns to control voltage source inverters substantially helped the development of modern electric drives used in various applications. Although the DSP control is well known, there are few papers that cover in detail the control signal generation methodology. This paper presents a DSP-based algorithm to generate sinusoidal PWM signals. The sinusoidal PWM generation algorithm is written in C language so it can be reused easily, in addition to the flexibility it provides in terms of changing the PWM switching frequency and the fundamental frequency of the inverter output voltage. The algorithm development methodology and the experimental results are presented. The output voltage and current harmonic spectra are compared for 5 kHz and 10 kHz carrier frequencies. The results show the effectiveness of the proposed algorithm. This work is part of a research project that aims to develop sensorless vector control of induction machines. This part is presented separately to document DSP based PWM algorithm development process.

- by Pierre Sicard and +1
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- Digital Signal Processing, Fundamental Frequency, Vector control, Development Methodology

This paper presents a mathematical modeling that uses the concept of harmonic inductances to derive voltage and torque equations of a three-phase induction machine using a, b, c and A, B, C formulation. Phase currents and electromagnetic torque are obtained by numerical integration of equations considering any supply voltage waveform. Two cases were studied -operation of induction motor supplied with sinusoidal waveform, and operation of an induction motor supplied by a three-phase inverter.

- by Jose Camacho
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- Harmonic Analysis, Simulation, Electromagnetic Induction, Reference Frame

A method for determining the signatures of dynamic eccentricity in the airgap force distribution and vibration pattern of induction machine is presented. The radial electromagnetic force distribution along the airgap, which is the main source of vibration, is calculated and developed into a double Fourier series in space and time. Finite element simulations of faulty and healthy machines are performed. They show that the electromagnetic force distribution is a sensible parameter to the changes in the machine condition. The computations show the existence of low frequency and low order force distributions, which can be used as identifiable signatures of the motor condition by measuring the corresponding low order vibration components. These findings are supported by vibration measurements and modal testing. The low frequency components offer an alternative way to the monitoring of slot passing frequencies, bringing new components that allow to discriminate between dynamic eccentricity and rotor mechanical unbalance. The method also revealed a non linear relationship between loading, stress waves and vibration during dynamic eccentricity.

- by A. Arkkio and +2
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- Electrical Engineering, Low Frequency, Finite element simulation, Induction machine

This paper sheds light on the additional harmonic components arising from broken bars fault in the stator line current of an induction machine, which are generalized and analyzed in a different manner than of those given in the literature. Special attention is focused on the effect of both motor slots and rotor dissymmetry on the mechanism of the generation of the different harmonic components with consideration of the unbalance voltage supply and speed ripples effects. Aside from the well-known diagnosis signatures, new ones show up. The simulation and experimental results confirm the aforementioned study.

- by Abdelmalek Khezzar
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- Engineering, Industrial, Fault diagnosis, Induction machine

The subject of machine condition monitoring is charged with developing new technologies to diagnose the machinery problems. Different methods of fault identification have been developed and used effectively to detect the machine faults at an early stage using different machine quantities, such as current, voltage, speed, efficiency, temperature and vibrations. One of the principal tools for diagnosing rotating machinery problems has been the vibration analysis. Through the use of different signal processing techniques, it is possible to obtain vital diagnostic information from vibration profile before the equipment catastrophically fails. A problem with diagnostic techniques is that they require constant human interpretation of the results. The logical progression of the condition monitoring technologies is the automation of the diagnostic process. The research has been underway for a long time to automate the diagnostic process. Recently, artificial intelligent tools, such as expert systems, neural network and fuzzy logic, have been widely used with the monitoring system to support the detection and diagnostic tasks. This paper reviews the progress made in electrical drive condition monitoring and diagnostic research and development in general and induction machine drive condition monitoring and diagnostic research and development, in particular, since its inception. Attempts are made to highlight the current and future issues involved for the development of automatic diagnostic process technology.

- by Ahmed Saleh
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- Signal Processing, Fuzzy Logic, Condition Monitoring, Neural Network

In permanent magnet (PM) synchronous machines, iron losses form a larger portion of the total losses than in induction machines. This is partly due to the elimination of significant rotor loss in PM machines and partly due to the nonsinusoidal flux density waveforms in the stator core of PM machines. Therefore, minimization of iron losses is of particular importance in PM motor design. This paper considers the minimizing of iron losses of PM synchronous machines through the proper design of magnets and slots, and through the choice of the number of poles. Both time-stepped finite element method (FEM) and the iron loss model from a previous study are used in this paper to draw the conclusions. . His main interests are power-semiconductor-controlled electric drives and power-electronics circuits, and the application of programmable electronics circuits in this field. He has a strong interest in laboratories for power engineering to support graduate research and education in engineering.

- by Chris C Mi
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- Finite Element Methods, Finite element method, FEM, Finite Element Analysis